(1) No person shall be convicted of any offence except for violation of the law in force at the time of the commission of the act charged as an offence, nor be subjected to a penalty greater than that which might have been inflicted under the law in force at the time of the commission of the offence

(2) No person shall be prosecuted and punished for the same offence more than once

(3) No person accused of any offence shall be compelled to be a witness against himself

Note:

Article 20 has taken care to safeguard the rights of persons accused of crimes. Persons here means the citizens, non-citizens as well as corporations. Please note that this article can not be suspended even during an emergency in operation under article 359. Article 20 also constitutes the limitation on the legislative powers of the Union and State legislatures.

Ex-Post facto Law Article 20 (1) says that no person shall be convicted of any offence except for violation of a law in force at the time of the commission of the Act charged as an offence, nor be subjected to a penalty greater than that which might have been inflicted under the law in force at the time of the commission of the offence. This is called Ex-Post facto Law. It means that legislature can not make a law which provides for punishment of acts which were committed prior to the date when it cam into force. This means that a new law can not punish an old act.

Doctrine of Double Jeopardy

Article 20(2) says that no person shall be prosecuted and punished for the same offence more than once. This is called Doctrine of Double Jeopardy. The objective of this article is to avoid harassment, which must be caused for successive criminal proceedings, where the person has committed only one crime. There is a law maxim related to this – nemo debet bis vexari. This means that no man shall be put twice in peril for the same offence. There are two aspects of Doctrine of Jeopardy viz. autrefois convict and autrefois acquit. Autrefois convict means that the person has been previously convicted in respect of the same offence. The autrefois acquit means that the person has been acquitted on a same charge on which he is being prosecuted. Please note that Constitution bars double punishment for the same offence. The conviction for such offence does not bar for subsequent trial and conviction for another offence and it does not matter the some ingredients of these two offences are common.

Self Incrimination Law

Article 20(3) of the constitution says that no person accused of any offence shall be compelled to be a witness against himself. This is based upon a legal maxim which means that No man is bound to accuse himself. The accused is presumed to be innocent till his guilt is proved. It is the duty of the prosecution to establish his guilt.